xe2x80x9cAccelerated hemodialysis: a new safe and simple method of a high filter low patient blood flow rate hemodialysisxe2x80x9d Elhatw Mohamad K. M. RENAL FAILURE (21) 5 1999.
presented as a talk in the first African Pediatric Nephrology Association meeting in Cairo, March 2000.
presented as a Poster in the 34 European Pediatric Nephrology Association meeting in Helsinki June 2000.
xe2x80x9cAccelerated hemodialysis connectionsxe2x80x99 Egyptian patent office filed on May 20, 1998 No 547.5.1998 Approved, Under print. Applicant: Dr. Mohamed Khaled Mohamed El Hatw.
xe2x80x9cThe calibrated recirculation valvexe2x80x99 Egyptian patent office filed on Aug. 5, 2000 No 1008 8 2000 Applicant: Dr. Mohamed Khaled Mohamed El Hatw.
1. The Old Art
Hemodialysis is done by passing the patient""s blood in semiperniable capillaries or plates impregnated in a physiological solution where toxins pass to the refreshing solution and is discarded.
In the traditional double needle hemodialysis the blood passes in different parts of the circuit by a constant speed that is controlled by the speed of the blood pump.
An average speed is selected in the normal situations whereas a slow speed is selected in patients with cardiovascular instability and in children while a rapid speed is selected in heparin free dialysis.
2. Defects in the Old Art
With slow blood flow rate the blood is liable for clotting as its movement is a major factor in preventing blood clotting.
With high filter blood flow rate the patient is liable for cardiovascular instability and heart failure as the dialysis is considered an extra effort load on the heart.
To conclude the high speed is hazardous to the patient while the slow speed is hazardous to the blood and the filter.
Accelerated hemodialysis lines are new lines of hemodialysis which allow controlled partial recirculation of blood from the venous to the arterial line leading to acceleration of blood flow through the filter without increase of the actual patient blood flow.
The regulator of blood flow in the pump controlled accelerated hemodialysis lines is the additional pump while in the pressure controlled lines the regulator is a valve which is either a blood flow rate controlled valve (Doppler flow meter controlled) or a blood lines pressure controlled valve (The calibrated recirculation valve).
The calibrated recirculation valve is a valve used to control the diameter of the recirculation segment in the pressure controlled acceleration hemodialysis lines by using specific calibrations for each particular line, the calibrated recirculation valve allows DIRECT adjustment of the patient blood flow.
The valve may be operated manually with the calibration inbuilt in the valve or supplied in separate graphs or it may work automatically under control of a the computer program prefed with these calibrations This program may be inbuilt in the hemodialysis machine or supplied in a separate computer.
Any of the usual forms of externally compressing or internally obstructing valves can be used. The line kinking valve is a valve that externally control the diameter of flexible lines by manual or automatic controlled kinking of the lines.